THE life and times of Apple founder Steve Jobs is a "heroic" tale. But a much-anticipated biopic, launched at the Sundance Film Festival and starring Ashton Kutcher as the Californian technology guru, makes an "almighty mess" of telling it.

jOBS throws a harsh spotlight on Kutcher’s "poverty of skills" as a serious actor, writes Sebastian Doggart in the Daily Telegraph. "His diction is incoherent. He clumsily signposts every emotion he thinks his character should feel: smug smiles for triumph; exaggerated scowls for disgust; nail-biting for anxiety."

The Guardian’s Ed Gibbs is more supportive of Kutcher who, he says, gives a "surprisingly effective turn as the man, down to his awkwardly hunched posture". But the film is "overly saccharine" and hamstrung by a script which reduces the other characters to shadows and sheds little light on what made Jobs "tick".

"This is far from the bomb some would have envisaged," says Gibbs in a two-star review, "but neither is it the character illumination one would wish for."

jOBS, directed by Joshua Michael Stern, follows the Apple founder’s life from his days as a "smelly, horny" student in Oregon to his game-changing creation of the Apple II computer with his friend and fellow geek Steve Wosniak (played by Josh Gad). We see him launch the iPod to universal acclaim and set Apple on the path that leads to the iPad and global domination.

Wozniak voiced his criticism of the film last week after a trailer was shown at Sundance. He claimed the on-screen relationship between the two men was "totally wrong", and said that ideas about "computers affecting society" came from him not Jobs

CNET’s Casey Newton says the film’s main failing isn’t Kutcher’s performance, but the script’s "fawning" portrayal of the Apple founder who died from cancer at the age of 56. The movie ignores his well-documented predilection for "yelling", missing deadlines and overspending budgets by millions. "There is great drama to be found in all that, but it is not to be found in the saccharine jOBS," writes Newton.

The Hollywood Reporter’s Justin Lowe agrees, calling the film a "two-hour commercial" for the tech giant.

Some critics are pinning their hopes for a more revealing portrait of Steve Jobs on a second, as yet unreleased, biopic directed by Aaron Sorkin, who made The Social Network. In the meantime, jOBS will be released in the US on 19 April. No release date for the UK has been set.